During a machining or manufacturing process, a joined structure may be assembled by joining coplanar first and second layers to form an interface between the first and second layers. Additionally, such a process may include assembling the joined structure with another element. For example, portions of a machine, such as an aircraft, having such a joined structure may be assembled with other portions of the machine. As such, in order to assemble the joined structure with the other portion, an orifice may be formed in the joined structure. The orifice may extend through the interface between the first layer and the second layer and through the first and second layers as well. Forming the orifice in the joined structure may produce burrs, structural anomalies and/or the like proximate the interface between the first layer and the second layer. Such anomalies are known to reduce fatigue characteristics of a workpiece.
To improve the fatigue performance of the interface between the first layer and the second layer, the joined structure may be subjected to a deburring process. Some deburring processes may include disassembling the joined structure such that the first layer and the second layer are removed from one another and then removing/cutting away the burrs about the orifice/hole through each of the respective layers. Other such deburring processes may utilize a cutting edge to trim and/or remove burrs at the interface between the first layer and the second layer within the orifice, without disassembly thereof. For example, one deburring process may include cutting away a portion of the joined structure proximate the interface between the first layer and second layer disposed within the orifice with a cutting tool, thereby removing the burred structure. However, such deburring processes may adversely impact the fatigue resistance of the joined structure proximate the interface due to removal of material if the cutting tool is not precisely positioned with respect to the interface. Accordingly, a need exists to improve the fatigue performance of an interface between a first layer and a second layer within an orifice/hole defined by a joined structure without adversely affecting the fatigue resistance of the structure proximate the interface.